As you already know, i hope, MySQL 4.1 is now cetificated a s a stable product release and may be used in a production enviroment.
This might be a good thing for most of us as 4.1 has several features that might be helpfull.

However there are several issues with PHP4 and MySQL 4.1

After installing and configuring the server you might get the following error message

This is due to PHP4 using an old version of mysql library... MySQL 4.1 has a completely different authentication method, then 4.0

This might seem impossible to some of you to fix. But there IS a solution

And id like to share it with you, in case you still dont know about it.The easiest way would be using mysql administrator. There you will have to go to server settings and set Use Old Password to checked.

Then you will have to re-assign all the passwords so that they will be saved the way you want to.

Finaly the third way:Start mysqld with the --old-passwords option. Assign an old-format password to each account that has had its password updated to the longer 4.1 format. You can identify these accounts with the following query:

PHP has a new extention that is designed to work with MySQL 4.1.3 and above.

As far as i can see this module is accessible only in PHP 5.
This module is called Improved MySQL Extention: mysqli

You can simply load that module and use it instead of mysql module. (most (not sure if not all) versions have mysql module built-in)

Note: you will have to use mysqli_query and similar instead of mysql_query.

I must say that the use of MySQL 4.1.8 is now recommended as it gives more sequrity and a faster database. Its easy to configure and absolutely no problems in managing with MySQL Administrator that is freely available from mysql.com for download.

As MySQL.com itself recommends all Windows XP users to use MySQL Administrator while Win98/NT/2000 to use WinMySQLAdmin utility.